Contouring toothbrush head

ABSTRACT

A toothbrush having two head sections, the sections being normally biased to assume an angle with respect to each other, to thereby define a generally concave bristle tip configuration. The two sections of the head have facing ends joined by a thin bridge section integral with the two heads. In one embodiment, there is one bridge section near the lower surface of the head. In another embodiment, there are two longitudinally spaced bridge sections each near the lower head surface. In a third embodiment, the bridge section is a thin integral connection between facing ends of the two sections. In other embodiments, the two head sections are normally aligned and are also joined by a thin, integral bridge section, with the bristles of the head section most remote from the handle being of uniformly different lengths. The space between the two facing ends is filled with an elastomer, typically SANTOPRENE (brand). The two head sections define an articulated head. In yet another embodiment, the bridge section is omitted.

This application is a continuation of application Ser. No. 09/090,331,filed May 29, 1998, which application is a continuation of applicationSer. No. 08/762,783, filed Dec. 10, 1996, now U.S. Pat. No. 5,758,383,which claims priority under 35 U.S.C. §119(e) of provisional applicationNo. 60/008,734, filed Dec. 29, 1995, which applications are incorporatedby reference herein.

BACKGROUND OF THE INVENTION

This invention relates to a toothbrush and more particularly to atoothbrush head construction wherein the head is designed and configuredto yield a brushing surface conforming to curved sections of teeth andwhich is bendable to conform to straight teeth sections.

Prior toothbrush constructions include toothbrush heads having pivotedor articulated sections joined together in a variety of constructions,such as a resilient strip of metal or the like, and also include pivotedor hinged articulated sections to provide a curved bristleconfiguration.

A curved/angled bristle surface configuration offers improved access tohard-to-reach areas such as the lingual surfaces of the front teeth, andbehind the rear molars, placing more bristles in contact with the outersurfaces of the front teeth.

Many current brushes which have rigidly mounted bristles and a rigidcurved/angled bristle surface exhibit an inherent disadvantage whenbrushing both flat as well as concave tooth surfaces. Placing acurved/angled bristle surface on flat tooth surfaces results in fewerbristles making contact with the teeth. These fewer bristles mustsupport the brushing forces applied through the handle, which willresult in premature splaying of the bristles. Some current toothbrusheshave a "power tip" configuration (elongated rigidly mounted tipbristles) which are claimed to have improved access benefits.

SUMMARY OF THE INVENTION

According to the invention, an articulated toothbrush head is defined bytwo head sections joined by one or more thin bridges of the same resinfrom which the toothbrush is formed, as by molding, to produce anintegral construction. These thin bridges permit limited flexing betweenthe two head sections, the two sections normally being at a small anglewith respect to each other. That portion of the head between the twohead sections may be, in one embodiment, in the general form of a Tshaped slot running transversely of the top surface of the head, fromone side head side edge to another. The slot is filled, as by injection,with an elastomer to control and enhance flexing. The construction issuch that the head section most remote from the handle is normallytilted with respect to the head section nearest the handle, the latterhead section located at one end of the handle. In a second embodiment,the head section may assume the form of a narrow cylindrical portion, orin a third embodiment two thin bridges may be employed, both havingelastomer.

An advantage of the present flexible configuration is, in addition tothe above noted features of a curved configuration, its inherentgentleness on the gums. When one brushes along the gumline with a powertip configuration, one focuses much of the force through theconcentrated area at the raised tip. With the present configuration,this force is more evenly distributed.

There are considerable manufacturing efficiencies with having theelastomer material of this invention used in the flex area being thesame elastic material as that which may be used as a grip material inthe handle area. Therefore, a configuration which allows flexing underthe loads typically encountered during brushing with materials which aresuitable for use as a grip would be desirable.

To achieve the flexibility described above, the cross section ofelastomer may be convoluted, with one or more convolutes. To aid infixing the elastomer to the toothbrush head sections, the elastomer maybe configured to fit into one or more slots on both ends of the flexingarea.

To minimize the gap between bristle tufts when the head is flexed into aflat configuration, it is desirable to position the plastic (resin)bridge between the tip and handle portions as near the bristle tips aspossible. This bridge is straightened during flexing, and directlycontrols the gap between bristle tufts on each side of the flex area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view illustrating the toothbrush head ofthis invention according to a first embodiment.

FIG. 2 is a top plan view of the toothbrush head shown at FIG. 1.

FIG. 3 is an elevational view showing the head and tufts of bristles asbrushing the inside surfaces of the lower teeth.

FIG. 4 is a view similar to FIG. 1 and slows an second embodiment.

FIG. 5 is a view similar to FIG. 1 and shows a third embodiment.

FIG. 6 is a side elevational view of a fourth embodiment.

FIG. 7 is a side elevational view of a fifth embodiment.

FIG. 8 is a side elevational view of a sixth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, a side elevational view of a toothbrushembodying the features and construction of this invention is shown in avertical position, with a portion of the handle designated as 12. Whilenot completely shown, the reader will understand that the handle extendsdownwardly and has a longitudinally axis. That portion of the headnearest the handle is designated as section 14 and is co-linear with thehandle, while that portion of the head most remote from the handle isdesignated as section 16. An elastomer section or joint between facingends of sections 14 and 16 is denoted generally as 18. A plurality oftufts of bristles 20 extends at right angles to section 14, while asimilar plurality of tufts of bristles 22 extends at right angles fromsection 16. Tufts of bristles 22 are thus at right angles to lowersurface 24 of head section 16, while tufts of bristles 20 areperpendicular to lower or bottom surface 26 of head section 14.

A generally T-shaped groove, in longitudinal cross section, extendstransversely across the upper or top surface of the head and is thuslocated between sections 14 and 16. The bottom of the central or mainpart of the groove is spaced from the lower surface of the compositehead, leaving a thickness or bridge section designated as 30 which joinsthe lower portions of the two head sections. Bridge or zone 30 istypically of a thickness between 20 and 40 thousandths of an inch. Thehandle and head sections are molded from a plastic or resin such aspolypropylene. The generally T shaped groove is filled with a resilientand soft thermoplastic elastomer. The T groove has two symmetrical wingportions 32, each terminating in an enlarged portion 34, the latterextending towards respective groups of tufts of bristles. The middle ofthe T shaped resin insert section 18 includes an integral ridge 36,while the lower portion or base portion of the T section is designatedas 38. The thermoplastic elastomer which forms section 18 may be athermoplastic vulcanate (TPV) consisting of a mixture of polypropyleneand EPDM (ethylene propylene diene monomers) which is available asSANTOPRENE (brand), described in U.S. Pat. No. 5,393,796 issued toHalberstadt et al, or VYRAM (brand), another TPV consisting of a mixtureof polypropylene and natural rubber, both SANTOPRENE and VYRAM (brands)being elastomers marketed by Advanced Elastomer Systems. Other suitableelastomers include KRATON, a brand of styrene block copolymer (SBC)marketed by Shell, and DYNAFLEX G 2706 (brand), a thermoplasticelastomer marketed by GLS Corporation and which is made with KRATON(brand) polymer. These and other suitable elastomers have, typically, aShore A hardness of from about 13 to 94, with about 29 being a preferredhardness. Grooves 40, on the top surface of the composite head, extendon both sides of raised rib or ridge 36, and border sections 32. FIG. 2further illustrates the construction. It is seen that elastomer section18 spans the width of the head sections.

In the normal configuration of the head, it is seen that head section 16is tilted with respect to head section 14 at an angle α, typically about18°. Thus, a force exerted on the brush during brushing is required totilt section 16 if it is to be more nearly or completely aligned withsection 14. The two head sections may be molded in their angledconfiguration as shown at FIG. 1, with the elastomer then added.Alternatively, the two head sections may be molded aligned with eachother and then angled upon locating or injecting the elastomer betweenthem.

Referring now to FIG. 3, it is seen that the effective curvature of thetwo head sections 14 and 16 offers improved access to inner and rearsurfaces of the teeth. Thus, handle 12 need not be inclined as much asotherwise in order for forward section 16 and its bristles 22 to engageinterior surfaces of the lower front teeth. In brushing a straightsection of teeth, the deformability of the elastomer section 18 permitssection 16 to partially or completely align itself with handle 12 andsection 14.

FIG. 4 illustrates a second embodiment of the invention, there shown ashorizontally disposed, and similar to that of FIGS. 1 and 2 except for adifferent construction for angularly joining the two head sections. Theelastomer joint is again denoted as 18, with the elastomer itselfdenoted as 50 and being of the same composition as previously set out,and extends across the width of the head, and is located between thefacing ends of sections 14 and 16. A thin integral bridge connectioncentrally between the two sections is designated as 52, typically beingof cylindrical form in transverse cross section. Each end is integralwith a respective head section. The elastomer is seen as completelysurrounding bridge 52. This bridge connection may be, in transversecross section, or any desired form. A top plan view of the head would besimilar to FIG. 2, except for the absence of grooves 40 and rib 36. Asseen at FIG. 4, the extent of the elastomer along the toothbrushlongitudinal axis is shorter than that of FIGS. 1 and 2. Integralconnection or bridge 52 performs the same function as bridge 30 of FIG.1, namely, integrally joining the two head sections.

FIG. 5 shows a third embodiment, again shown as horizontal. There, thelower surfaces 24 and 26 of bristled head sections 14 and 16 are joinedby an intermediate arcuate bottom surface 27 having tufts of bristles 23extending orthogonally and downwardly therefrom. An elastomer section 18is generally C shaped and has a bight part 60 and tips or ends 62, thelatter located in respective complementary double troughs or doublegrooves which extend transversely across the head. The elastomer tipsare separated by head portion 64, with thin bridges 66, again formedfrom the molded resin forming the toothbrush, joining the two headsections at the lower surface of the whole head. The C shaped elastomerthus surrounds portion 64 across the width of the head.

The second and third embodiments yield the same cleaning action as shownat FIG. 3. The thickness of bridges 52 and 66 is the same as that ofbridge 30 of FIG. 1.

It is seen that the bridges 30, 52 and 66 of the respective embodimentsinhibit longitudinal separation of the two head sections by resistingtensile or other forces which might result in such separation, while theelastomer also controls the degree of flexing when head section 16 issubject to brushing forces. The function of the bridges is thus totether the two head sections together, as well as to set them at aninitial angle. When the sections move toward straightening or alignment,each elastomer section is deformed. Such deformation is resisted by theelastomer and to a lesser extent by the resin (polypropylene) bridges sothat the sections revert to their normal, angled relationship upon thecessation of brushing force on forwardmost section 16.

FIG. 6 illustrates a fourth embodiment which differs from that shown inFIG. 1 only in the absence of bridge 30 of FIG. 1. Instead of bridge 30,the two head sections are coupled by T shaped elastomer section 39, thelatter being of the same form as that of section 38 of FIG. 1, exceptthat it extends all the way to the lower surface of the head.

FIG. 7 shows a fifth embodiment, here the two head sections 14 and 16being normally aligned. A generally T shaped elastomeric section 41forms a joint 18 which fills the spaces between the ends of the two headsections 14 and 16, except for bridge 30, identical with bridge 30 ofFIG. 1, which integrally tethers the two head sections together. Tuftsof bristles 70 are slanted with respect to lower head surface 24 of headsection 16, the slanting being towards handle 12. Tufts 70 are ofsuccessively different lengths, with the longest being near the mostremote free end or tip of the head section 16. It is seen that the tipsof bristle tufts 70 and 20 form a generally concave brushing surfacewhich is at times, during brushing, flattened upon bending of joint 18.

FIG. 8 illustrates a sixth embodiment, similar to that of FIG. 7, anddiffers therefrom only in that the head section 16 tufts, here denotedas 72, extend orthogonally from surface 24. These latter tufts are, astufts 70, of uniformly different lengths. The longest are near the freeend of head section 16.

Again, the free ends of tufts 72 and 20 form a generally concavebrushing surface which is at times, during brushing, flattened uponbending of joint 18.

Many toothbrushes available in the marketplace today are "dualcomponent," by which is meant that an elastomeric material is used to agreater or lesser extent, particularly in the finger gripping portion ofthe brush 28, shown in FIG. 3. The method of manufacture of such dualcomponent brushes by injection molding is thus exceedingly well known inthe art today. The toothbrushes according to the present invention maybe made by use of such conventional dual component technology. Forexample, in accordance with a first method of manufacturing brushesaccording to the present invention, the elastomeric material may beintroduced into the head area from the handgrip area via a molded-inchannel (assuming a handgrip area is required). Alteratively, theelastomer could be introduced into the head area via a second injectionpoint or gate located at the head, thereby eliminating the need for amolded-in channel. The head may then be tufted using conventional stapletechnology.

In accordance with a second method of manufacturing brushes according tothe present invention, the handle and elastomer for the grip and thehead areas are molded using a three-shot molding technique. Theelastomer is introduced into the head area separately from the handgriparea. This process is especially useful if the elastomer for the headsection of the brush and the hand grip section are different elastomericmaterials, such as elastomers having two different Shore hardnessvalues. For example, in some circumstances, it may be desired to use asofter elastomer for the head area than fore the handgrip portion of thebrush. As above, the head may then be tufted using conventional stapletechnology.

I claim:
 1. A toothbrush comprising:a handle; and an articulated headjoined to the handle, the articulated head including a first section anda second section, at least part of the handle, the first section and thesecond section being integrally molded of the same material, the firstsection including a first plurality of tufts of bristles and the secondsection including a second plurality of tufts of bristles, the firstplurality of tufts of bristles extending orthogonally from the firstsection and the second plurality of tufts of bristles extendingorthogonally from the second section, the first section and the secondsection being the only sections of the articulated head includingbristles, the first section being the only one of said sections joinedto the handle, the second section being joined to the first section byat least one bridge, the second section, in a normal configuration ofthe articulated head, being angled with respect to the first section. 2.The toothbrush of claim 1, wherein:the second section is angled at anangle of about 18°.
 3. The toothbrush of claim 1, wherein:the handle,first section and second section are made of polypropylene.
 4. Thetoothbrush of claim 1, wherein:the first section is co-linear with thehandle.
 5. The toothbrush of claim 1, wherein the first section is theonly one of said sections directly joined to the handle.
 6. A toothbrushcomprising:a handle; and an articulated head joined to the handle, thearticulated head including a first section and a second section, atleast part of the handle, the first section and the second section beingintegrally molded of the same material, the first section including afirst plurality of tufts of bristles and the second section including asecond plurality of tufts of bristles, the first plurality of tufts ofbristles extending orthogonally from the first section and the secondplurality of tufts of bristles extending orthogonally from the secondsection, the first section and the second section being the onlysections of the articulated head including bristles, the first sectionbeing joined to the handle, the second section being joined to the firstsection by at least one bridge, the second section, in a normalconfiguration of the articulated head, being angled with respect to thefirst section, the articulated head including an elastomer between thefirst section and the second section.
 7. The toothbrush of claim 6,wherein:the elastomer is made of a thermoplastic vulcanate.
 8. Thetoothbrush of claim 6, wherein:the elastomer is made of a styrene blockcopolymer.
 9. The toothbrush of claim 6, wherein:the handle includes agrip, and wherein the elastomer and the grip are formed of the samematerial.
 10. The toothbrush of claim 6, wherein:the elastomercompletely surrounds the at least one bridge.
 11. A method of producinga toothbrush comprising:molding, of one material, a toothbrush handlealigned with and integrally joined to an articulated head, thearticulated head including only a first and a second section, the firstsection being joined to the second section by at least one bridge;angling the first section with respect to the second section; injectingan elastomer between the angled first and second sections to form anangled joint between the first section and the second section; tuftingboth the first section and the second section each with a plurality oftufts, whereby the tufts extend orthogonally from the first section andthe second section.
 12. A method of producing a toothbrushcomprising:molding, of one material, a toothbrush handle aligned withand integrally joined to an articulated head, the articulated headincluding only a first section and a second section, the first sectionbeing joined to the second section by at least one bridge, the firstsection and second section being molded at an angle with respect to oneanother; injecting an elastomer between the angled first and secondsections to form an angled joint between the first section and thesecond section; tufting both the first section and the second sectioneach with a plurality of tufts, whereby the tufts extend longitudinallyfrom the first section and the second section.
 13. A toothbrushcomprising:a handle; and an articulated head joined to the handle, thearticulated head including a first section and a second section, atleast part of the handle, the first section and the second section beingintegrally molded of the same material, the first section including afirst plurality of tufts of bristles and the second section including asecond plurality of tufts of bristles, the first plurality of tufts ofbristles extending orthogonally from the first section and the secondplurality of tufts of bristles extending orthogonally from the secondsection, the first section and the second section being the onlysections of the articulated head including bristles, the first sectionbeing joined to the handle, the second section being joined to the firstsection by at least one bridge, the second section, in a normalconfiguration of the articulated head, being angled with respect to thefirst section, wherein the articulated head includes an elastomerbetween the first section and the second section, and wherein theelastomer completely surrounds the at least one bridge.
 14. Thetoothbrush of claim 13, wherein:the second section is angled at an angleof about 18°.
 15. The toothbrush of claim 13, wherein:the handle, firstsection and second section are made of polypropylene.
 16. The toothbrushof claim 13, wherein:the elastomer is made of a thermoplastic vulcanate.17. The toothbrush of claim 13, wherein:the elastomer is made of astyrene block copolymer.
 18. The toothbrush of claim 13, wherein:thehandle includes a grip, and wherein the elastomer and the grip areformed of the same material.
 19. The toothbrush of claim 13, wherein:thefirst section is co-linear with the handle.
 20. The toothbrush of claim13, wherein:the second section, when a force is exerted during brushing,is nearly aligned with the first section.
 21. A toothbrush comprising:ahandle; and an articulated head joined to the handle, the articulatedhead including a first section and a second section, at least part ofthe handle, the first section and the second section being integrallymolded of the same material, the first section including a firstplurality of tufts of bristles and the second section including a secondplurality of tufts of bristles, the first plurality of tufts of bristlesextending orthogonally from a first side of the first section and thesecond plurality of tufts of bristles extending orthogonally from a sideof the second section, the first section and the second section beingthe only sections of the articulated head including bristles, the firstsection being the only one of said sections that is joined to thehandle, the second section being joined to the first section by at leastone bridge, the second section, in a normal configuration of thearticulated head, being angled with respect to the first section, the atleast one bridge being near the side of the first section from which thetufts of bristles extend and the side of the second section from whichthe tufts of bristles extend.
 22. The toothbrush of claim 21,wherein:the second section is angled at an angle of about 18°.
 23. Thetoothbrush of claim 21, wherein:the handle, first section and secondsection are made of polypropylene.
 24. The toothbrush of claim 21,wherein:the first section is co-linear with the handle.
 25. A toothbrushcomprising:a handle; and an articulated head joined to the handle, thearticulated head including a first section and a second section, atleast part of the handle, the first section and the second section beingintegrally molded of the same material, the first section including afirst plurality of tufts of bristles and the second section including asecond plurality of tufts of bristles, the first plurality of tufts ofbristles extending orthogonally from a side of the first section and thesecond plurality of tufts of bristles extending orthogonally from a sideof the second section, the first section and the second section beingthe only sections of the articulated head including bristles, the firstsection being joined to the handle, the second section being joined tothe first section by at least one bridge, the second section, in anormal configuration of the articulated head, being angled with respectto the first section, the at least one bridge being near the side of thefirst section from which the tufts of bristles extend and the side ofthe second section from which the tufts of bristles extend, thearticulated head including an elastomer between the first section andthe second section.
 26. The toothbrush of claim 25, wherein:theelastomer is made of a thermoplastic vulcanate.
 27. The toothbrush ofclaim 25, wherein:the elastomer is made of a styrene block copolymer.28. The toothbrush of claim 25, wherein:the handle includes a grip, andwherein the elastomer and the grip are formed of the same material. 29.A toothbrush comprising:a handle; and an articulated head joined to thehandle, the articulated head including a first section and a secondsection, at least part of the handle, the first section and the secondsection being integrally molded of the same material, the first sectionincluding a first plurality of tufts of bristles and the second sectionincluding a second plurality of tufts of bristles, the first pluralityof tufts of bristles extending orthogonally from the first side of thesecond plurality of tufts of bristles extending orthogonally from thesecond section, the first section and the second section being the onlysections of the articulated head including bristles, the first sectionbeing joined to the handle, the second section being joined to the firstsection by at least one bridge, the second section, in a normalconfiguration of the articulated head, being angled with respect to thefirst section, the second section being moveable relative to the firstsection by a brushing force.
 30. The toothbrush of claim 29, wherein thearticulated head including an elastomer between the first section andthe second section.
 31. The toothbrush of claim 29, wherein at least onebridge being near the side of the first section from which the tufts ofbristles extend and the side of the second section from which the tuftsof bristles extend.